The present invention pertains to a device for the catalytic cleaning of or soot removal from internal combustion engine exhaust gases, comprising a housing that has two open end zones connected to an exhaust gas line and a flow passage for the exhaust gas between the end zones. Two flow-carrying exhaust gas treating bodies are held in the housing at spaced locations from each other, and a rigid protective ring is provided surrounding the space between the two exhaust gas treating bodies on the outside.
In a prior-art device of this type for the catalytic cleaning of exhaust gas, the protective ring consists of a high temperature-resistant sheet metal which surrounds the two connected exhaust gas treating bodies--ceramic monoliths with catalytically active coating in the prior-art device--at least in the end zones adjoining the protective ring. The connections between the protective ring and the two monoliths are problematic, because high local stresses occur there, and difficult-to-control relative movements occur between the protective ring and the exhaust gas treating bodies during operation because of the thermal expansion at the high exhaust gas temperatures.
A device for catalytic cleaning of exhaust gases, in which the exhaust gas treating bodies are ceramic: monoliths with catalytically active coating, is known from West German Auslegeschrift No. DE-A 36,26,728. Among other things, a rigid protective ring is described there, whose end faces are in contact with the two adjoining exhaust gas treating bodies and whose cylindrical outer circumferential surface is aligned with the outer circumferential surfaces of the two adjoining exhaust gas treating bodies.